Temperature Profiling of Secondary LED Optics by Infrared Thermography
Over the last few years, the power density of white LEDs has increased dramatically. Whilst there are large efforts to optimize the thermal management and thus the temperature stability of the LEDs, less attention is paid to the temperature of the secondary optic. Peter W. Nolte, Franziska Steudel, Bernd Ahrens, Nils J. Ziegeler, Frank Drees, Horst Rudolph, and Stefan Schweizer from the Fraunhofer Application Center for Inorganic Phosphors, the South Westphalia University of Applied Sciences, and the Innovations-and Technologycenter GmbH, TRILUX Group respectively, have approached this issue. They investigated the temperature profiles of polymethyl methacrylate (PMMA) and polycarbonate (PC) secondary optics and they discuss the results.
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A New Approach for Fast and Accurate Measurement of Light Emitting Diodes Junction Temperatures
LpR 73 Article, page 48: Junction temperature of LEDs is one crucial parameter to being thoroughly observed. In this paper, Ahmet Mete Muslu, Onuralp Isil and Prof. Mehmet Arik from the Energy Efficient Electronics and Lighting Technologies Center (EVATEG), Department of Mechanical Engineering at the College of Engineering Ozyegin Universitywill at first describe the importance of Tj for LED systems including RGB and white LEDs. Then they will present techniques from literature and recently in-house developed novel methods and a new Junction Temperature Measurement Device (EVAtherm). Results in selected general lighting and automotive lighting applications will be demonstrated.
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Thermal and Optical Challenges for SSL in Automotive Applications
LpR 72 Article, page 50: Solid State Lighting changed the lighting environment in automotive lighting almost more than in the field of general lighting. While efficiency of the devices increased and every few weeks new improvements are reported, thermal management remains crucial and a critical part of the system. Umut Zeynep Uras, Ahmet Mete Muslu and Mehmet Arik, from the Energy Efficient Electronics and Lighting Technologies Center (EVATEG), Department of Mechanical Engineering, College of Engineering at Ozyegin University, and Fatih Goren from the FARBA Corporation, explain the dependencies between photometric, electrical and thermal parameters of an automotive lighting application.
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Get Your Thermals Sorted
Long-lasting LED solutions require superb thermal design – Forge ensures the thermal design is a fundamental design process for every LED solution they manufacture.
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MIT Researchers Developed New Heat Conducting Polymer Films
Polymers are usually the go-to material for thermal insulation. Think of a silicone oven mitt, or a Styrofoam coffee cup, both manufactured from polymer materials that are excellent at trapping heat. Now MIT engineers have flipped the picture of the standard polymer insulator, by fabricating thin polymer films that conduct heat — an ability normally associated with metals. In experiments, they found the films, which are thinner than plastic wrap, conduct heat better than many metals, including steel and ceramic.
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Materials, Manufacturing and Technologies for Designing Passive Cooling Devices
Until recently, incandescent bulbs and fluorescent lights were the dominant light sources. Today it’s the energy efficient, durable and, in the meantime, cost effective, LED. But to achieve these attributes appropriate cooling is still necessary and due to progress over the last few years the need for active cooling solutions is limited to a few high power applications as long as the material and technology is carefully chosen. John Broadbent, Managing Director at Columbia-Staver Ltd., describes the different technologies and materials and gives practical advice on how to find the right solution for an application.
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Automatic Panel Level Transient Thermal Tester
LpR 67 Article, page 44:The thermal resistance junction in case is an important parameter for the reliability of LEDs because degradation of the LED is temperature driven. Simulation and testing has advanced over the past few years but transient thermal analysis (TTA), which is required to understand the thermal transfer path, is especially work and time consuming - and not automated. Gordon Elger, Professor for Electronic Manufacturing Technologies, Technische Hochschule Ingolstadt, and his co-authors, Maximilian Schmidt, Alexander Hans, and Dominik Müller, present and discuss an automatic panel level TTA tester. They explain the challenges and the solution and demonstrate the applicability of using LED test board-panels.
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Intended for High-Performance Computer Chips - Maybe Also Useful for LEDs
The inner workings of high-power electronic devices must remain cool to operate reliably. High internal temperatures can make programs run slower, freeze or shut down. Researchers at the University of Illinois at Urbana-Champaign and The University of Texas, Dallas have collaborated to optimize the crystal-growing process of boron arsenide – a material that has excellent thermal properties and can effectively dissipate the heat generated in electronic devices.
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Thermal Simulation Tool for LED Design Requirements
Light-emitting diodes (LEDs) are used and accepted in many areas of lighting technology today.
But without the right thermal design, LED lamps would not be viable. Chris Aldham, Development
Manager at 6SigmaET explains why keeping key components within narrow temperature limits is often
critical, why this makes thermal simulation important to LED device designers, and how to select the
right thermal management simulation tool for this task.
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Thermal Issues Posed by Compact Packaging and IoT for Next Generation SSL
Besides general lighting, LEDs are penetrating many areas. At the same time, Internet of Things (IoT)
has been rapidly evolving. Added electronics are expected to add an additional 70% to overall heat
generation. Therefore, solving thermal problems will become more important again; on a par with
footprint area and cost. Prof. Mehmet Arik, Director of EVATEG Center for Energy Efficient Electronics
and Lighting Technologies at the Ozyegin University, and Umut Zeynep Uras, master student at the
Ozyegin University, present some of the current, local, hotspot thermal issues caused by tight
packaging. The severity of the problem for future lighting systems with added IoT will also be discussed.
Finally, possible technologies to meet those challenges will be shown.
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Looking for the Best Thermal Solution for CSP Module Designs
Chip Scale Package (CSP) LED technology is not new but while it has been used for a while in TV
backlighting applications, it is relatively new to lighting applications. In many respect CSPs are a new
world for lighting module manufacturers as they are smaller, usually don’t have any ESD protection,
have different light distribution, and, last but not least, have a smaller heat dissipation area. The latter
asks for re-thinking the traditional thermal design for modules. Dr. Giles Humpston, Applications
Engineer at Cambridge Nanotherm, explains in detail why CSP LEDs present a significant thermal
challenge for module designers and outlines some fundamentals in calculating the thermal flow required
to keep CSP LEDs cool.
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Smartcells - Enabling Fast and Accurate Electronics Thermal Design
This white paper introduces the concept of SmartCells™ in the context of Computational Fluid Dynamics (CFD) simulation software. They exist in FloTHERM XT™, a CAD enabled electronics cooling simulation tool supplied by Mentor Graphics (Ref 1). This document will explain what they are, how they differ from other meshing approaches employed in the CFD industry, and their benefits to CFD users and electronics thermal designers.
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Thermal Management of an LED Light Source for Microscopes
Thermal management is a challenge for every LED and LASER solution. Microscope lighting solutions
have some very critical requirements, especially if they concern medical applications. ESCATEC in
Heerbrugg, Switzerland has a lot of experience in that field and covers all relevant technical disciplines.
Wolfgang Plank, head of the MOEMS Future Laboratory and cleanroom, and Gerd Harder, Key Account
Manager, give insights on the design process, thermal simulation and production of an LED light source
for Leica Microsystems’ Ophthalmic Microscope Proveo 8.
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Engineered “Sand” May Help Cool Electronic Devices and LEDs
Giorgia Tech Research reports that Baratunde Cola, associated professor at the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology, would like to put sand into your computer and other electronic devices. Not beach sand, but silicon dioxide nanoparticles coated with a high dielectric constant polymer to inexpensively provide improved cooling for increasingly power-hungry electronic devices.
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Litecool Turns LED Packaging on Its Side
Litecool has produced LED packages in a vertical orientation rather than horizontal. This means that the dielectric layers only have a minor impact on the thermal performance of the LED package and allow the heat to escape more effectively through the metallic parts of the package. This has significant benefits for flip-chip packaging where dielectric layers are usually very close to the diode.
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